WowAce

When sorting by Namelist in the latest beta. Not sure if I understand it correctly as it seems to work more like a filter. If I add a name, any person in the group/raid thats not in that list won't appear in the raidframes anymore?

Would be cool if it would possibly work whereby names in the list simply get shown first in the order of the list. Meaning if you add a single name in the list, it would always be displayed as the first frame, then the rest. 

Correct, Namelists are filters, you can use the the namelist order too, selecting "NameList" in the "Sort By:" selection editbox.

The addon is using the builtin game namelist management code, this code does not support the behavior you are requesting.